Coupling device for the connecting a tractor engine to a trailer vehicle

ABSTRACT

The invention relates to a coupling device for the coupling of a trailer vehicle to a tractor engine, comprising, on the tractor engine, a coupling body ( 10 ), with an insertion opening ( 11 ) and pneumatically-operated coupling bolt ( 12 ) and, on the trailer, a drawbar ( 20 ), with a drawbar eye ( 21 ), for the passage of the coupling bolt ( 12 ). A tubular piece ( 13 ) is arranged below the coupling body ( 10 ), coaxially rotating about the geometrical axis (Z-axis) of the coupling bolt ( 12 ), at the lower end of which a cylindrical shell ( 15 ) is embodied at an angle of 90° to the geometrical axis (X 1 -axis) of the coupling bolt ( 12 ). A rotating cylindrical piece ( 16 ) is arranged in the shell ( 15 ), with a block ( 17 ), embodied on the free peripheral section thereof, with pins ( 18 ) for electrical connections and at least two hollow guide bolts ( 19 ) for pneumatic and mechanical connection with a bush piece ( 22 ), projecting from the trailer, arranged on the free front face thereof. The bush piece ( 22 ) is arranged below the drawbar ( 20 ) such as to rotate about two axes (Y 2  and X 2 ), perpendicular to each other and is provided with bushes ( 23 ), for accommodating the pins ( 18 ) and bushes ( 24 ) for accommodating the guide bolts ( 19 ).

The invention relates to a coupling device for the coupling of a trailervehicle to a tractor, comprising, on the tractor, a coupling body withan insertion opening and pneumatically operable coupling bolt, and, onthe trailer, a drawbar with a drawbar eye for the passage of thecoupling bolt.

There are known so-called trailer couplings, wherein the eye of thedrawbar is inserted into the insertion opening of the coupling body andthe coupling bolt is operated pneumatically thereafter such that it islocated in the coupled condition inside of the eye of the trailer.However, with such a coupling electrical and pneumatic connections mustbe established by hand, in order to be able for example to perform thebraking and vehicle direction indications in controlled manner and tooperate the brakes.

The present invention is intended to provide a coupling of the typeindicated above, in which it is not required any more that anyconnecting processes must be performed manually and that both, when atrailer is to be coupled and a trailer is to be uncoupled.

This is achieved by the features given in the characterising parts ofthe patent claims, namely that, below the coupling body, a tubular pieceis arranged, which is coaxially rotatable with regard the geometricalaxis (Z-axis) of the coupling bolt, at the lower end of which acylindrical half shell is formed at an angle of 90° to the geometricalaxis (X₁-axis) of the coupling bolt,

a cylindrical part is arranged in the half shell coaxially accommodatedtherein and coaxially (axis X₁) rotatable thereto, with a block formedon the free peripheral section thereof, with pins for electricalconnections as well as at least two hollow guide bolts for pneumatic andmechanical connection with a bush part projecting from the trailerarranged on the free front face thereof, and

the bush part is arranged below the drawbar flexibly connected therewithswivelling about two axes (Y₂ and X₂) perpendicular to each other, andis provided with bushes for accommodating the pins and bushes foraccommodating the guide bolts.

In one embodiment of the invention an intermediate piece is movablyarranged, which comprises passages for the pins.

Furthermore, the bush part can be hinged swivelling around itslongitudinal axis (X₂) in transverse direction to the drawbar and aroundits transverse axis (Y₂) parallel to the drawbar.

In the coupling device the coupling and uncoupling operation can beperformed from the driver's cabin, without any outside operations beingnecessary. This is achieved substantially in that both at the couplinghousing and at the drawbar co-operating bush plug connections areprovided, which can be connected with each other electrically as well aspneumatically. Since it usually cannot be assumed that the trailervehicle is aligned in the driving direction towards the tractor, therespective coupling elements must be arranged such that they canaccommodate misalignments. Therefore, the plug part at the tractor aswell as the bush part at the trailer vehicle are moveable in multipleaxes. It is obvious that the plugs can be arranged in correspondingmanner at the trailer vehicle and the bushes correspondingly at thetractor.

The invention is illustrated below by way of example with reference tothe drawing.

FIG. 1 shows an isometric illustration of the parts of the couplingaccording to the invention just before a coupling process.

FIG. 2 shows, in altered scale, a vertical sectional view through thecoupling device according to the invention.

FIG. 3 shows a plan view onto the coupling device, wherein trailervehicle and tractor are not aligned with each other.

FIG. 4 shows a vertical sectional view through the coupling body, theinsertion opening and the drawbar of a modified embodiment of theinvention.

FIG. 5 shows a diagrammatic view of the parts shown in FIG. 4 obliquelyfrom above.

In the figures, 10 indicates the coupling body formed in known mannerwith an insertion opening 11 for reception of a drawbar 20 with adrawbar eye 21. The ideal relationships of the mutual arrangements ofthese parts can be taken from FIG. 2, wherein it can be assumed thatthis condition does hardly occur in practice, because, on the one hand,the tractor and the trailer vehicle are not aligned in a commondirection, in the driving direction. On the other hand, the road isusually not plane such that the drawbar eye 21 is tilted from thehorizontal plane.

In the figures, the vertical geometrical axis of a tension boltrecognisable in the elevation according to FIG. 3 and having thereference number 12, has been indicated as Z. The associatedperpendicular direction corresponding to the driving direction of thetractor has been indicated as Y₁. The transverse direction to thedriving direction of the tractor has been indicated as X₁, such that aspatial trihedral can be recognised from FIG. 1 consisting of X₁, Y₁ andZ.

Below the coupling body 10 a pivot 14 projects coaxially downwards tothe Z-axis or to the axis of the coupling bolt 12, respectively. A tubeor tubular piece 13 sits on this pivot 14 such that this can performrotary motions around the Z-axis or the longitudinal axis of thecoupling bolt 12, respectively. The tubular piece 13 terminates in thelower area with a half shell part 15, the interior of the half shell 15extending perpendicularly to the Z-axis, i.e. is oriented towards theaxis X₁ extending transversely to the driving direction of the tractor.

A cylindrical part 16 is received in the half shell 15 such that it canimplement rotary or swivelling motions around its longitudinal axis X₁.In the FIGS. 1 and 2 slots can be recognised in the shell 15, throughwhich the screws connected with the cylindrical part 16 pass, such thatthe cylindrical part 16 is securely accommodated in the interior of theshell part 15, but both parts can swivel with regard to each other.

At its free front face and substantially in backward direction, that isaligned towards the axis Y₁, a block 17 is mounted at this partialcylinder 16, which substantially comprises the shape of a cuboid. Insideof this block 17 electrical as well as pneumatic connecting lines arelocated. A plurality of plug pins 17 project from the front face of theblock 17 directed backwards, which can form electrical connections withthe bushes 23. Furthermore, hollow bolts 19 project from the front face2, which can co-operate with receiving parts 24 in the bush part 22.

The hollow bolts 19 are connected internally with a compressed airsource such that they can transfer in the coupled condition compressedair from the tractor to the trailer vehicle in order to operate andrelease the brakes.

Two sliding pieces or intermediate pieces 31 are attached on the hollowbolts 19, which are reciprocal towards the axis Y₁ and are intended tofacilitate the process for insertion of the plug 18 and of the hollowbolts 19 into the associated bushes 23 and 24.

Two pins or pivots 29 are fixed diametrically with regard to each otherat the outwardly standing end of the drawbar 20, and that in transversedirection with regard to the geometrical axis of the drawbar. Thisdirection of the drawbar 20 is indicated as Y₂. In the properly coupledcondition, the axis Y₁ coincides with the axis Y₂, otherwise the drawbar20 can assume any other direction, of course.

Rods 26 directed downwards to both sides are attached on the pivot 29,which can perform swivelling motions around the axis 28 of the pivots29.

A longitudinal hole 27 is located at each lower free end of the rods 26,wherein two pivots 25 are received in these longitudinal holesprojecting towards the two small side rims of the bush part 22therefrom. The axis of the pivots 25 is indicated as X₂, said axis X₂being aligned in parallel with the axis X₁, when the coupling processhas been finished.

By arranging the pivots 25 inside of the longitudinal holes 27, it ispossible that the bush part 22 performs swivelling motions around itstransverse axis Y₂ and rotary motions around its axis X₂.

Thus, the coupling process is performed such that the drawbar 20 isinserted into the insertion opening 11 (FIG. 2). In this process theparts 17 and 31 of the tractor together approach the bush part 22. Sincethe hollow bolts 19 project the furthest from the block 17 towards Y₁,they first get into the associated bushes 24 of the bush part 23. It canbe seen in FIG. 1 that the hollow bolt 19 shown therein is provided witha conical shape to facilitate this insertion process. In a furthermovement of the block 17 with the intermediate piece 31 towards the bushpart 22, a series of correcting operations can be performed. Thus, theblock 17 and the intermediate piece 31 can perform rotary motions aroundthe Z-axis and around the axis X₁. Simultaneously, the block 23 canperform swivelling motions around its axes Y₂ and X₂ such that finallythe condition shown in section in FIG. 2 can be reached. As the partscoupling bodies and the parts 17 and 31 are flexibly connected withregard to each other, and as the bush body 22 is also flexibly arrangedwith regard to the rods 26 and thus with regard to the drawbar 20, thedrawbar 20 can also bear onto the lower surface of the insertion opening11 and the square shown in FIG. 2 can modify to a parallelogram, withoutany mechanical stresses occurring or without any negative influences onthe implemented electrical and pneumatic line connections.

Not shown in the figures are final position sensors or switchesreporting the condition shown in FIG. 2 to the driver's cabin such thatthe electrical connections can be connected through from there and forexample the brakes can be subject to compressed air.

In FIG. 3 the plan view onto the coupling in the coupled conditions canbe seen, and that for the case that a substantial misalignment betweenthe driving direction of the tractor (Y₁-axis) and the alignment of thedrawbar 20 (axis Y₂) exists. Also this condition is not problematic withregard to the electrical and pneumatic and mechanical couplingconnections. However, it is of special importance for the vehicle driverin the automatic coupling process, to know this angle of misalignment inorder to initiate respective starting processes. For this purpose anangle indication can be arranged below the coupling body 10 and thetubular piece 13. Looking at FIG. 2, it can be seen that at this placethe angle between these parts can be detected as rotational displacementaround the Z-axis and can be transferred into the driver's cabin indigital form such that the driver performs the respective correctingmovement either by hand, or this rotational displacement between trailervehicle and tractor is independently detected by a respective vehiclecontrol.

It is pointed out that this misalignment between drawbar and tractor canbe in the range of ±45°, while the other mentioned rotary or swivellingmotions are in the range of less than ±25°.

The embodiment of the invention shown in FIG. 4 and FIG. 5 shows detailsof the suspension of parts to be connected with each other on thedrawbar 20. The reference numbers used up to now have been chosen therefor the same parts as well.

A rotary body 201 is set onto the drawbar 20, which can perform rotarymotions around and concentric with the axis of the drawbar. For this itis only required, to set a bush-like part resisting rotation onto thedrawbar, onto which in turn a concentrically arranged part is rotatablymounted. This concentrically arranged part 201 is provided with two arms202 projecting initially radially outwards from the outer circumferenceof the part 201 and then merging arc-shaped into parts alignedsubstantially axial-parallel. These axially aligned parts are aligned attheir free projecting ends with the usual coupling connections, whichhave been indicated for example in FIG. 2 with 17, 31, 22 as well as 23and 24.

Substantial for the functioning of the parts 201 and 202 is that acoupling of the parts 31 with the parts 22 is possible, and that also inthe case, when the drawbar 20 is twisted around its axis in one or theother direction. This situation occurs, when the trailer vehicle doesnot stand on a plane surface, but the one side is elevated with regardto the other vehicle side.

The parts 202 could for example be mounted swivelling at the bush 201 bymeans of a pivot, or the parts 22 could be swivelling through a commonhorizontal axis extending in transverse direction to the tractor. Basedon this Cardan's suspension a compensating process can occur here.

It is shown in FIG. 4 as well, in which manner the angular position canbe detected, that is when the trailer vehicle and the tractor are not ina straight position to each other during coupling. This situation can berecognised in FIG. 5, which shows that the tractor with the insertioncoupling 10 is at an angle to the axis of the drawbar 20. This situationarises in that the tractor has not been or cannot be brought into thealigned position before the coupling process, because the approach wayis blocked by a different vehicle.

It can be seen from FIG. 4 that a bush 13 is rotatably attached on thedownward extending projection 14 of the coupling body 10, which isrotatable around the axis Z of the insertion coupling 10. A radialprojecting part 103 is attached to the bush 13, and a box-shaped sensorhead 102 with Hall sensors is arranged thereon.

A disk 101 is attached to the coupling body 10, at the outercircumference of which magnetic traces, preferably in form of a graycode, are arranged. Since the disk 101 assumes a fixed position withregard to the coupling body 10, and since the sensor head 102 can betwisted relatively to the axis of the coupling body 10, it is obviousthat by means of the Hall sensors and the magnetic traces the angle ofthe misalignment can be detected, wherein this is the angle between thelongitudinal vehicle axis of the tractor and the axis of the tractordrawbar. This angle is of importance for starting processes after thecoupling process and that especially, when this starting process is tobe performed independently.

1. A coupling device for the coupling of a trailer vehicle to a tractor,comprising, on the tractor, a coupling body (10) with an insertionopening (11) and a pneumatically operable coupling bolt (12) and, on thetrailer, a drawbar (20) with a drawbar eye (21) for the passage of thecoupling bolt (12), characterized in that, below the coupling body (10),a tubular piece (13) is arranged, which is coaxially rotatable withregard to the geometrical axis (Z-axis) of the coupling bolt (12), andat the lower end of which a cylindrical half shell (15) is formed at anangle of 90° to the geometrical axis (X₁ axis) of the coupling bolt, acylindrical part (16) is arranged in the half shell (15) coaxiallyaccommodated therein and coaxially (axis X₁) rotatable thereto, with ablock (17) formed at the free peripheral section thereof, with pins (18)for electrical connections as well as at least two hollow guide bolts(19) for pneumatic and mechanical connection with a bush part (22)projecting from the trailer arranged at the free front face thereof andthe bush part (22) is arranged below the drawbar (20) and flexiblyconnected therewith swivelling around two axes (Y₂ and X₂) perpendicularto each other, and is provided with bushes (23) for accommodating thepins (18) and bushes (24) for accommodating the guide bolts (19).
 2. Thecoupling device according to claim 1, characterized in that on the guidebolts (19) an intermediate piece (31) is movably arranged, in that onthe guide bolts (19) an intermediate piece (31) is movably arranged,which comprises passages for the pins (18).
 3. A coupling deviceaccording to claim 2, characterized in that the bush part (23) is hingedswivelling around its longitudinal axis (X₂) in a transverse directionto the drawbar (20) and around its transverse axis (Y₂) parallel to thedrawbar.
 4. A coupling device according to claim 3, characterized inthat the bush part (23) is hinged swivelling around its longitudinalaxis (X₂) in a transverse direction to the drawbar (20) and around itstransverse axis (Y₂) parallel to the drawbar.